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Installing Madwifi on Slackware

Madwifi
Wireless support in Slackware has much improved in the last few releases. The madwifi driver for Atheros based chipsets works fine with both the 2.4.x and the 2.6.x series of kernels. If you want unencrypted or WEP-protected connections, everything should work right away.
If you need WPA encryption, read the Support for WPA encryption section of this page.

This Wiki page explains how to install an appropriate Madwifi package on your Slackware computer, and gives directions on how to build your own. The focus lies on using the new madwifi code, also known as “madwifi-ng” or “madwifi next-generation”. The name used for the driver is just “madwifi” and where needed, I will refer to “madwifi-old” for the old code which is no longer being developed (but fixes are still being applied).

The madwifi driver is capable of creating so-called virtual access points or VAPs. This is being done on a base device called wifi0 which will show up in your listings of ifconfig and iwconfig, and is not linked to the wireless extensions. You should never have to use this wifi0 network device. The user station (a VAP of type “sta”) will by created by default when the kernel module loads and is called ath0. This ath0 is the real network device, which you will be configuring and using.
People who want to create something other than a user station, for instance a real Access Point (master mode) will want to read this MadWiki documentation.

Obtaining slackware packages for madwifi

Binary Slackware packages for the madwifi driver can be found at slackware.com. They can be installed onto your computer using installpkg or upgradepkg. They are packages for specific kernels. The package naming convention is madwifi-${VERSION}_${KERNELVERSION}-i486-${NUMBER}.tgz. Here, ${VERSION} is the version of the madwifi source package, and ${KERNELVERSION} is the version of the kernel that the package is meant for. The ${NUMBER} is the build number. In case there are multiple packages where only the build number differs, then the package with the highest build number is the most recent and should be used.

The old driver, also referred to as “madwifi-old”, still has some features that have not yet been ported to the “madwifi-ng” code. For people who need this old driver specifically, there is a package still available here.

Building a slackware package for madwifi from source

You can build your own package for any kernel version that you are running, too. If you want to know if any of the downloadable packages matches your running kernel, you can check the version of your running kernel with the command

uname -r
  • Start with downloading all the source files here to a directory on your local hard disk. This command will do exactly that:
    lftp -c "open http://www.slackware.com/~alien/slackbuilds/madwifi/; mirror build"

    This will create a subdirectory build in your current directory. Change to that directory, su - to root if you haven't done so already, and start the madwifi.SlackBuild script after making it executable:

    chmod +x madwifi.SlackBuild
    ./madwifi.SlackBuild

    The binary package will be created in directory /tmp and have a name of madwifi-${VERSION}_${KERNELVERSION}-i486-1.tgz. Here, ${VERSION} is the version of the madwifi source package, and ${KERNELVERSION} is the version of your running kernel.

  • If you want to build a package for another kernel that youve already installed on your computer, and you don't want to reboot into that kernel for building the madwifi package, you can run the script like this (the example builds a package for Linux kernel 2.6.13):
    KVER=2.6.13 ./madwifi.SlackBuild

    If the kernel source tree cannot be found (i.e. if the kernel source tree is not found where the link /lib/modules/${KVER}/build points) you can specify your kernel source directory as well (again, this is only an example):

    KVER=2.6.13 KSRC=~/src/linux-2.6.13 ./madwifi.SlackBuild

    If you downloaded a newer/other version of the madwifi sources and you want to build a package out of that, you will have to edit the madwifi.SlackBuild script, and substitute the correct value for the VERSION in the line

    VERSION=<value>

    before executing the script.
    Be warned that the madwifi sources are in constant development, so the possibility exists that the madwifi.SlackBuild script will not produce correct results for newer (or older) madwifi sources.

  • Install the madwifi package with
    installpkg madwifi-VERSION_KERNELVERSION-i486-BUILDNR.tgz

    or if you already had a previous package installed, use

    upgradepkg madwifi-VERSION_KERNELVERSION-i486-BUILDNR.tgz

Loading the kernel modules automatically

You can use hotplug to load the madwifi driver automatically. There is nothing to configure; hotplug takes care of everything. If you do not use hotplug, you can add a line like this to /etc/rc.d/rc.modules:

/sbin/modprobe ath_pci

which will then load the kernel module when the computer boots.

Network configuration

rc.wireless.conf

If you have a Wireless Access Point that is broadcasting its station ID (the ESSID), and is not configured for encrypted traffic, then youre ready to go with the default configuration as it comes with Slackware. This kind of open wireless network is typical when

  1. you just took your Wireless Access Point out of the box you were sold it in, and didnt have time yet to configure it;
  1. you are at an airport/hotel/pub where they offer free wireless access.

If you need to configure specific parameters to make the wireless card talk to your Access Point - for instance, the ESSID (in case the Access Point is hiding its station ID), or the channel, or a WEP key, etc) then you will need to edit the file

/etc/rc.d/rc.wireless.conf

and add a specific configuration that matches your wireless card and Access Point.

You will notice that the content of /etc/rc.d/rc.wireless.conf is basically a number of sections that apply to certain (ranges of) wireless network cards. The distinguishing factor is the hardware address (the MAC address) of a card. A section for a specific card or range of cards looks like this:

  MAC_Address)
      INFO="a string that decribes your card type"
      PARAMETER1="value1"
      PARAMETER2="value2"
      [more parameters] .......
      ;;

The MAC_Address in this example can be a full MAC address (six hex bytes separated by colons, like 00:12:8E:A0:32:DC) that matches a single network card, or a wildcard address that matches a whole range of cards, typically all cards from a specific vendor (like 00:12:8E:A0:*).
You are going to add such a section for your card, and this is how to do it:

  • After the module is loaded and your ath0 interface is available, run ifconfig ath0 and get the MAC address of ath0.
  • Edit /etc/rc.d/rc.wireless.conf and comment out this section right in the beginning of the file:
      *)
          INFO="Any ESSID"
          ESSID="any"
          ;;

    so that it will look like this:

    # *)
    #     INFO="Any ESSID"
    #     ESSID="any"
    #     ;;
  • Somewhere further below the lines you just commented out, add a few lines (easiest is to add it to the bottom of the file for instance, right above the esac line) that will apply to your card, like these:
      00:06:25:13:2B:D4)
          INFO="D-LINK DWL-G510 revB1"
          ESSID="yourapessid"
          KEY="0100030203"
          ;;

    The first line is your card's MAC address followed by a ')', and the last line must be two semicolons all by themselves (copy and paste one of the available examples if you're unsure).
    Your MAC address, ESSID, KEY and info comment are obviously going to be different.

rc.inet1.conf

Slackware 10.2 understands network interfaces whose names do not start with eth. A network card that shows up as ath0 can not be setup with an IP address using the configuration files that are part of pre-Slackware 10.2 releases. We are going to assume here that you are running Slackware 10.2. For older releases, read Updating the network scripts and Configuration the manual way.

  • You will need to add or modify a few lines in /etc/rc.d/rc.inet1.conf in order to get a configuration like this:
    # Config information for ath0 (using dhcp):
    IFNAME[1]="ath0"
    IPADDR[1]=""
    NETMASK[1]=""
    USE_DHCP[1]="yes"
    DHCP_HOSTNAME[1]="mywirelessbox"

    Or like this:

    # Config information for ath0 (using static IP address):
    IFNAME[1]="ath0"
    IPADDR[1]="192.168.3.11"
    NETMASK[1]="255.255.255.0"
    USE_DHCP[1]=""
    DHCP_HOSTNAME[1]=""
    GATEWAY="192.168.3.1"

    These are example values of course and you will have to substitute your own.

  • NOTE
    In the above example, where I used the index 1, like in: VARIABLENAME[1], you may use whatever index is not used. If you do not have an eth0 interface for instance, you might as well want to use the unused 0 array index. The last configuration example would then look like this:
    # Config information for ath0 (using static IP address):
    IFNAME[0]="ath0"
    IPADDR[0]="192.168.3.11"
    NETMASK[0]="255.255.255.0"
    USE_DHCP[0]=""
    DHCP_HOSTNAME[0]=""
    GATEWAY="192.168.3.1"

    Obviously, any array index value ([0],[1],[2], ) in /etc/rc.d/rc.inet1.conf should be used for exactly one cards configuration. If you copy a set of lines, be sure to change the array index to an unused value. If you forget this, and create a doublure, then Slackware will happily forget about all but the last values found in the file.

  • NOTE
    Any setting that is available in rc.wireless.conf can also be configured in rc.inet1.conf by prefixing the parameter with “WLAN_”. For instance, suppose you want to configure WPA. You could add the following to your card's section in rc.wireless.conf
WPA="wpa_supplicant"
WPADRIVER="madwifi"

but this is how you could do it in rc.inet1.conf as well:

IFNAME[1]="ath0"
   ...
WLAN_WPA[1]="wpa_supplicant"
WLAN_WPADRIVER[1]="madwifi"

You can configure your card in either one, or both of the configuration files, but the settings in rc.inet1.conf will always have priority. It depends on your own taste which of the two configuration files you want to put your configuration in.

(Re) starting the network interface

If you're using Slackware 10.2 or in case you run an older release but updated your network scripts, you can start your ath0 interface like this:

/etc/rc.d/rc.inet1 ath0_start

or restart it like this (after making changes to the above configuration files for instance):

/etc/rc.d/rc.inet1 ath0_restart

Earlier versions of Slackware will (re-)start all configured interfaces at once, because all you can run is

/etc/rc.d/rc.inet1

Updating the network scripts (Slackware 10.1 and older)

The network scripts of Slackware 10.2 can be used in older releases of Slackware as well. You will need /etc/rc.d/rc.wireless* and /etc/rc.d/rc.inet1*
If you have difficulties extracting these files from a Slackware 10.2 CD or Internet server, you can find them here too.

Network configuration the manual way (Slackware 10.1 and older)

These are the relatively easy ways to get slackware to bring up your interface:

  1. Run /etc/rc.d/rc.wireless to configure the wireless parameters for your card.
  2. Run dhcpcd ath0 which should be enough to get you up and running;
  3. It depends on your local network and your settings if you want ifconfig (instead of dhcpcd) and possibly additional iwconfig commands.
  4. Put a dhcpcd ath0 or ifconfig ath0 statement at the bottom of /etc/rc.d/rc.local
  5. If youre using hotplug, you can have it automatically bring up the interface by editing /etc/hotplug/net.agent and inserting the following lines in the case add|register) branch:
         ath*)
           dhcpcd -n $INTERFACE % If you use dhcp for the interface
           % or if you prefer to just hardcode your interface, put your ifconfig statement here.
           % ifconfig $INTERFACE 192.168.1.1 netmask 255.255.255.0 ...
           ;;

    In the remove|unregister branch it will automatically bring down dhcpcd if running.

Using early madwifi-ng versions with Slackware 10.2

NOTE:
The text in this paragraph applies to early versions of the madwifi-ng driver.
For any version of the madwifi driver released after 23-january-2006, the directions
given in this paragraph are no longer needed; when loading the kernel module
(/sbin/modprobe ath_pci), an interface ath0 will be automatically created,
and there is no longer a need to run wlanconfig (either manually or by modifying
the hotplug scripts). See the MadWiki page on VAP autocreate
if you want to know more about this.

Madwifi-ng's concept of virtual APs makes the configuration a bit more complicated, in particular if you have hotplugging enabled.
The reason is that the hotplugging subsystem sees at least two events each for adding and removing: one for the wifi0 device when the card is plugged in, and one for each activation of a virtual interface. When the events for the wifi0 device are received, wlanconfig needs to be executed to enable the virtual APs.
This can be accomplished by editing /etc/hotplug/net.agent and inserting a couple of lines, and adding a new script in the /etc/rc.d directory.

  1. Editing /etc/hotplug/net.agent, in the case add|register) branch:
         wifi*)
           exec /etc/rc.d/rc.madwifi-ng ${INTERFACE}_start
           ;;
  1. Editing /etc/hotplug/net.agent, in the “case remove|unregister)” branch:
         wifi*)
           exec /etc/rc.d/rc.madwifi-ng ${INTERFACE}_stop
           ;;
  1. Creating a new file, /etc/rc.d/rc.madwifi-ng, with the following content:
    #!/bin/sh
    # /etc/rc.d/rc.madwifi-ng
    # This script is used to bring up an Atheros wireless interface
    # Using the madwifi-ng code (http://www.madwifi.org/)
    #
    # Version 1.0
    # For Slackware 10.2 - Joe Feise 2005-Dec-15
    
    # Find the path where wireless tools are installed
    for IWPATH in /usr/{bin,sbin} /usr/local/{bin,sbin} /sbin /bin ; do
        if [ -x $IWPATH/wlanconfig ] ; then break ; fi
    done
    WLANCONFIG="$IWPATH/wlanconfig ath"
    
    ###########
    # LOGGING #
    ###########
    
    # If possible, log events in /var/log/messages:
    if [ -f /var/run/syslogd.pid -a -x /usr/bin/logger ]; then
      LOGGER=/usr/bin/logger
    else # output to stdout/stderr:
      LOGGER=/bin/cat
    fi
    
    #######################
    # INTERFACE FUNCTIONS #
    #######################
    
    # Function to bring up a wireless interface.  If the interface is
    # already up or does not yet exist (perhaps because the kernel driver
    # is not loaded yet), do nothing.
    if_up() {
      # If the interface isn't in the kernel yet (but there's an alias for it in
      # modules.conf), then it should be loaded first:
      if ! grep `echo ${1}: | cut -f 1 -d :`: /proc/net/dev 1> /dev/null ; then # no interface yet
        if /sbin/modprobe -c | grep -w "alias ${1}" | grep -vw "alias ${1} off" > /dev/null ; then
          echo "/etc/rc.d/rc.inet1:  /sbin/modprobe ${1}" | $LOGGER
          /sbin/modprobe ${1}
        fi
      fi
      if grep `echo ${1}: | cut -f 1 -d :`: /proc/net/dev 1> /dev/null ; then # interface exists
        if ! /sbin/ifconfig | grep -w "${1}" 1>/dev/null 1> /dev/null ; then # interface not up or not configured
          $WLANCONFIG create wlandev ${1} wlanmode sta
        else
          if [ "$DEBUG_ETH_UP" = "yes" ]; then
            echo "/etc/rc.d/rc.madwifi-ng:  ${1} is already up, skipping" | $LOGGER
          fi
        fi 
      else
        if [ "$DEBUG_ETH_UP" = "yes" ]; then
          echo "/etc/rc.d/rc.madwifi-ng:  ${1} interface does not exist (yet)" | $LOGGER
        fi
      fi
    }
    
    # Function to take down a wireless interface:
    if_down() {
      # Removing the modules
      sleep 2
      /sbin/modprobe -r ${1}
    }
    
    
    # Function to start the network:
    start() {
      if_up wifi0
    }
    
    # Function to stop the network:
    stop() {
      if_down wifi0
    }
    
    
    ############
    ### MAIN ###
    ############
    
    case "$1" in
    'start') # "start" brings up all configured interfaces:
      start
      ;;
    'stop') # "stop" takes down all configured interfaces:
      stop
      ;;
    'restart') # "restart" restarts the network:
      stop
      start
      ;;
    *_start) # Example: "wifi0_start" will start the specified interface 'wifi0'
      INTERFACE=`echo $1 | /bin/cut -d '_' -f 1`
      if_up $INTERFACE
      ;;
    *_stop) # Example: "wifi0_stop" will stop the specified interface 'wifi0'
      INTERFACE=`echo $1 | /bin/cut -d '_' -f 1`
      if_down $INTERFACE
      ;;
    *_restart) # Example: "wifi0_restart" will take 'wifi0' down and up again
      INTERFACE=`echo $1 | /bin/cut -d '_' -f 1`
      if_down $INTERFACE
      sleep 1
      if_up $INTERFACE
      ;;
    'up') # "up" does the same thing as "start"
      start
      ;;
    'down') # "down" does the same thing as "stop"
      stop
      ;;
    *_up) # "*_up" does the same thing as "*_start"
      INTERFACE=`echo $1 | /bin/cut -d '_' -f 1`
      if_up $INTERFACE
      ;;
    *_down) # "*_down" does the same thing as "*_stop"
      INTERFACE=`echo $1 | /bin/cut -d '_' -f 1`
      if_down $INTERFACE
      ;;
    *) # The default is to bring up all configured interfaces:
      if_up wifi0
    esac
    
    # End of /etc/rc.d/rc.madwifi-ng

    This takes care of creating a virtual AP as normal station mode, with device name athx (usually ath0). From this point forward, the normal rc.inet1 processing for athx, as explained above, takes place.

Support for WPA encryption

I am assuming that you already have your madwifi-powered card up and running. Do not try to add WPA support if you do not yet have a functional wireless network connection! Also, if you run Slackware older than 10.2 you will need the updated network scripts that are mentioned in the previous section Updating the network scripts (Slackware 10.1 and older).

The madwifi package obtained here is for a “madwifi-ng” version that I tested with the wpa_supplicant package also found here. People who want to use the old version of the madwifi driver can find a package here.
Be warned that in order to get WPA working with the “old” driver, I needed fairly old madwifi snapshots. Your mileage may vary.

If you want to compile your own packages, you might find some useful information in the Setting up a Client Using WPA-PSK Wiki page.

Note:
Recent wpa_supplicant should have support for roaming open networks as well
as for wpa-protected networks. This makes the waproamd
program obsolete for instance.
Note:
When you want to re-build wpa_supplicant, make sure you have installed
the madwifi package on your system as well. The wpa_supplicant build
needs the include files that thie madwifi package installs.
If you want to use the SlackBuild scripts for madwifi and wpa_supplicant
found here to rebuild the packages for your system,
build them in that order (first build and install madwifi, then build
and install wpa_supplicant).
The madwifi include files will be found by the wpa_supplicant build script.
  • To enable WPA support for your madwifi driver, install the wpa_supplicant package (it is not depending on any kernel version) and then open the file /etc/wpa_supplicant.conf in an editor. It should look something like this:
      ctrl_interface=/var/run/wpa_supplicant
      ctrl_interface_group=0
      eapol_version=1
      ap_scan=1
      fast_reauth=1
      
      network={
            scan_ssid=0
            ssid="your_essid"
            proto=WPA
            key_mgmt=WPA-PSK
            pairwise=CCMP TKIP
            group=CCMP TKIP WEP104 WEP40
            psk=your_64_hex_characters_long_key
      }

    but youll need to supply your own values for the ssid and the psk.

  • There is a way to generate the hexadecimal value for the PSK if you have an access point which uses a passphrase. As root, run:
    wpa_passphrase YOURSSID passphrase

    with the SSID of your AP and the passphrase youve entered in its WPA-PSK configuration. You'll receive an output, which looks like this:

    network={
        ssid="YOURSSID"
        #psk="passphrase"
        psk=04dffae0172e3a255e5bab6f28ab78cc23d845f3dd8d4a63ba64a37555e2a33b
    }

    Next, you should copy the three lines that you find inside the network={} section and paste them inside the network={} section of the file /etc/wpa_supplicant.conf. Do not forget to check the permissions of the configuration file! The key that it contains should be protected from prying eyes.

    chmod 600 /etc/wpa_supplicant.conf
  • You will also need to apply the following patch to /etc/hotplug/net.agent if you're not yet running Slackware 10.2. The patch makes the network initialization cleaner if you have more than one network interface, and wpa_supplicant needs that.
    --- net.agent.org       2005-04-17 00:48:48.000000000 +0200
    +++ net.agent   2005-04-17 00:41:56.000000000 +0200
    @@ -67,7 +67,7 @@
                     # Interface already up?  If so, skip.
                     if ! /sbin/ifconfig | grep "^${INTERFACE} " 1> /dev/null ; then
                         debug_mesg run rc.inet1
    -                    exec /etc/rc.d/rc.inet1
    +                    exec /etc/rc.d/rc.inet1 ${INTERFACE}_start
                     fi
                # RedHat and similar
  • Finally, youll need to upgrade your wireless-tools to at least wireless-tools-27 (which is in Slackware 10.2). There is a package for wireless-tools-28 here in case you need an even more advanced version (like I do).
  • Now, if your network configuration in rc.inet1.conf looked like this:
      # Config information for ath0 (using dhcp):
      IFNAME[1]="ath0"
      IPADDR[1]=""
      NETMASK[1]=""
      USE_DHCP[1]="yes"
      DHCP_HOSTNAME[1]="mywirelessbox"

    then youd have to add two lines so that it will read:

      # Config information for ath0 (using dhcp):
      IFNAME[1]="ath0"
      IPADDR[1]=""
      NETMASK[1]=""
      USE_DHCP[1]="yes"
      DHCP_HOSTNAME[1]="mywirelessbox"
      WLAN_WPA[1]="wpa_supplicant"
      WLAN_WPADRIVER[1]="madwifi"

    Adapt this to your own configuration of course.

  • You can restart your network card now, by running
    /etc/rc.d/rc.inet1 ath0_restart

    If your WPA connection does not activate, try some debugging:

WPA debugging

  • Was wpa_supplicant compiled with support for madwifi?
    Run wpa_supplicant on the commandline, and verify that the output mentions madwifi = MADWIFI 802.11 support (Atheros, etc.) under drivers:. If not, you will have to find another package which has the support for madwifi compiled in, or build a wpa_supplicant package yourself, and make sure that the build script finds the madwifi source code on your box.
  • Debug the WPA authentication process.
    Make sure the network interface is down (run
    /etc/rc.d/rc.inet1 ath0_stop

    to make sure). Start the wpa_supplicant daemon as a foreground process with additional debugging enabled:

    wpa_supplicant -dw -c/etc/wpa_supplicant.conf -Dmadwifi -iath0

    Then activate the network interface in another terminal (run

    /etc/rc.d/rc.inet1 ath0_start)

    Look at the output of wpa_supplicant in the first terminal, it might give you pointers to look for a solution.

  • Get a run-time status overview of the supplicant:
    As root, run
    wpa_cli status

    to see the current status of wpa_supplicants authentication process.

  • Debug Slackwares network intitialization.
    Add
    DEBUG_ETH_UP="yes"

    to /etc/rc.d/rc.inet1.conf and look for logger messages that are written to /var/log/messages. Maybe those messages will help you trace your problem.
    NOTE: with debugging enabled, Slackware will write your WEP/WPA keys to the message log as well!

  • The WPA association might take a long time.
    Start the interface again after a little time, this may help if it takes wpa_supplicant a long time to associate (no restart, just another start):
    /etc/rc.d/rc.inet1 ath0_start

    If this works, but it happens a lot, you can change the wait time for the WPA authentication process by editing the file /etc/rc.d/rc.wireless and changing the line

    WPAWAIT=10

    to

    WPAWAIT=20

    or any other larger value that helps your particular setup.

  • The Access Point is not broadcasting the SSID.
    I have tried and failed in getting WPA to work when the Access Point has a hidden SSID. Check if your AP is broadcasting the SSID and if not, enable it. There is little point in hiding the SSID anyway, with WPA as a protection layer you should not fear break-ins (as long as you do not use easy-to-guess passphrases!!! WPA can be cracked with dictionary attacks and no I will not supply a link here).

Author(s) and further pointers

  • The original information on this page was written by unknown author for the original DokuWiki based http://madwifi.org/wiki/MadWiki
  • This page was updated with Slackware 10.2 information and WPA configuration by Eric Hameleers <alien at slackware dot com>
    For questions about this page, you can contact me at my email address, or visit the #madwifi IRC channel on Freenode.
  • Updated with information about using madwifi-ng on Slackware 10.2 by Joe Feise <jfeise at feise dot com>.
  • Updated with information about using madwifi-ng (builds later than 1407) and updated WPA information by Eric Hameleers <alien at slackware dot com>.
  • Exported this page from the MadWiki and translated back to DokuWiki format, for my own Slackware Wiki.
 Installing Madwifi on Slackware ()
SlackDocs